Shares in Australia's biggest wealth manager AMP have tumbled to one-month lows after the firm said its wealth management cash flows slumped nearly 40 per cent, from $342 million to $209 million during the quarter.

The cash flow was negatively affected by weaker investor confidence, ongoing market volatility and adjusting to an enhanced regulatory environment, the firm said.

For the first quarter, AMP's total assets under management totalled $112.6 billion, down 2 per cent from the previous quarter.

"Domestic and global investment market conditions continued to be challenging during the first quarter, subduing cash flows across our business," chief executive Craig Meller said in a statement released to the ASX.

"Ongoing claims volatility continues to be a feature in Australian wealth protection."

Retail and corporate superannuation net cash flows fell to $383 million from $638 million from the previous corresponding period.

AMP's wealth protection business also took a loss of $18 million from insurance claims in income protection.

In a note, analysts at UBS said the re-emergence of "quite significant losses" in AMP's wealth protection arm is concerning.

"The absence of any meaningful losses from major bank competitors in recent weeks indicates higher incidence levels could be an AMP-specific problem with either assumptions or shape of its customer base," analysts James Coghill and Scott Olsson wrote.

UBS downgraded the stock from buy to neutral, and lowered their price target from $6.30 to $5.50.